Without limiting the scope of the present invention, its background will be described in relation to sand control screen assemblies operating in a wellbore that traverses a subterranean hydrocarbon bearing formation, as an example.
During drilling and construction of wellbores that transverse hydrocarbon bearing formations, it is oftentimes desirable to form a filter cake on the face of the formation to minimize damage to the permeability thereof. The filter cake often comprises an acid-soluble component (e.g., a calcium carbonate bridging agent) and a polymeric component (e.g., starch and xanthan). Before desirable fluids, such as hydrocarbons, may be produced from the formation, the filter cake generally is removed.
In one method of removal, a treatment fluid such as an acid or a fluid operable to react with an acid generating compound may be pumped downhole to remove the filter cake. It has been found, however, that this type of procedures may involve expensive additional trips in and out of the wellbore. For example, in completions including sand control screens, it may be necessary to trip a service tool assembly in and out of the well to perform the treatment operation. In such installations, the service tool assembly may permit fluid to be circulated through the sand control screens, potentially plugging or clogging the sand control screens. Alternatively, the service tool assembly may include a washpipe that is run inside and to the end of the sand control screens so that most of the fluid is circulated around the sand control screens. In these installations, however, the cost and time required to run the washpipe is undesirable.
In addition, during the installation of sand control screens, the filter media may be exposed to intense and adverse conditions that may degrade the mechanical integrity of the filter media. For example, fluid circulation through the filter media caused by the movement of the sand control screens downhole as well as contact between the sand control screens and the wellbore in long horizontal or deviated open hole completions may damage or plug the sand control screens as they are run downhole.
Accordingly, a need has arisen for a sand control screen that is operable to allow circulation of fluid therethrough without the need for additional trips into the well. A need has also arisen for such a sand control screen that is not susceptible to damage during installation. Further, a need has arisen for such a sand control screen that is operable to transport a treatment component to a desired location downhole.